Partially overlapped near user non-orthogonal multiple access (P-N-NOMA) has been proven as a promising scheme to reduce the disparity of rates among the NOMA users. P-N-NOMA improves the far user performance significantly and hence, is considered as a promising candidate for the scenario where both users have high rate requirements. In this paper, the performance of the P-N-NOMA scheme is investigated in terms of outage probability and sum-rate over \(\kappa - \mu\) fading channel. In particular, a two-user P-N-NOMA scheme is considered which uses two orthogonal sub-carriers with a flexible spectrum; one sub-carrier is used to accommodate both users through the NOMA scheme and another sub-carrier is used to accommodate only far user through orthogonal multiple access (OMA) scheme. The analytical and simulation results confirm that P-N-NOMA scheme improves the far user rate significantly which results in the reduced disparity of rates between near and far users. However, the performance improvement of the far user is subjected to the appropriate selection of overlapping ratio. The suitable range of power allocation coefficients and optimum power allocation coefficients are derived. The impact of fading parameters, imperfect successive interference cancellation (SIC), user pairing, and user scheduling on the performance of P-N-NOMA is also discussed.
